JPS5930572A - Double sides copying device with regulator for fixation pressure - Google Patents

Abstract

PURPOSE:To economize fixation heat and to improve the durability of a roll by having a blank mode by which a copy having a blank rear surface is obtd. and decreasing or releasing the pressurizing force on the roll pair of a fixation device with the heat roll when the blank mode is selectively executed. CONSTITUTION:Fixation device with the heat roll is so constituted that a backup roll 34b made of rubber is pressed to a heat roll 34a contg. a heater H from the lower side by means of a lever 34c and an eccentric pressurizing cam 34d. Oil is coated through felt 34e on the roll 34a. When a blank mode wherein paper without carrying any image thereon is discharged onto a tray for copying on double sides is selectively excuted, the pressurization of the roll 34b upon the roll 34a is decreased or released by the effect of a solenoid controlled by a control device. The fixation heat is thus economized whereby the decreased consumption of the oil and the prolonged life of the rolls are resulted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying apparatus that can be used for double-sided copying and single-sided copying.

In the case of single-sided copying, the side with the transferred image (this side is defined as the front side) is normally ejected with the side facing upwards, but in the case of double-sided copying, the side with the transferred image is It is ejected with the back side facing up and in the f'' position.For this reason, when double-sided copying is performed continuously in page order, if the last page of the document is hit an even number of times, the double-sided copy will be made. However, if it is an odd-numbered copy, the copy will be one-sided, so the last page will be ejected with the side that was copied facing up.In other words, the last page will be out of order and a blank side will be inserted between it and the previous page. That would be too sweet.

Therefore, even if the last page of the original to be copied is an odd number, the functions of the image forming devices are temporarily stopped and the functions of the image forming devices are temporarily stopped so that the copy is made on both sides, and the copy made later is a blank page. It was proposed that it should be set as ``mode'' (% Kaisho 5
4-18743). However, in this known copying device,
Even in the blank paper mode, the transfer paper is passed through the pressure fixing device as in the normal case. That is, in the blank paper mode, even though there is no need for fixing, the pair of fixing rolls is brought into pressure contact with each other in a normal fixable state. However, maintaining the pair of fixing rolls in a pressure-contact state that enables fixing even in the blank paper mode causes heat to be lost by applying heat to the transfer paper, even though there is no need for fixing. In this case, there is excess oil consumption, which also affects the durability of the fuser roll and other parts.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying apparatus that eliminates the above-mentioned drawbacks.

According to the present invention, it is possible to selectively use double-sided copying and single-sided copying, and in addition, when copying the back side, at least a part of the operating means is inactivated or copying is performed without going through at least a part of the image forming process. In a copying apparatus having a blank paper mode in which a copy with a blank back side can be obtained by conveying a material, when the blank paper mode is selected and executed, the pressing force of a pair of rolls of a heat roll fixing device is reduced or canceled. This is solved by

The specific example shown in the drawings will be explained below.

In the heat roll fixing device illustrated in FIG. 1, a rubber bank amplifier roll 34b is pressed from below against a heater roll 34a containing a heater H using a lever 34c and an eccentric pressure cam 34d. .

The transfer paper is configured to pass between 34b and 34b.
Oil is applied to the heater roll 34a all the way through the felt 34e. From this fixing roll,
The amount of heat supplied to the transfer paper for fixing is determined by the roll temperature T.
is determined by the nip time t. Here, the nip time t is defined as the nip width when the contact length t in the conveying direction where the heater roll 34a and the pump roll 3+b are in contact with each other is defined as the nip width, as shown in FIG. The width t is removed by the moving speed V of the transfer paper, and t = l/v
is given by FIG. 2 shows an example of the pressing force P and the amount of heat supplied to the paper. Since there is no need to supply heat in the blank paper mode, heat loss is reduced by reducing the nip time t. For this purpose, in the present invention, in order to reduce the nip width t in order to reduce the nip time t, the pressing force is lowered or made zero. This also means that the contact length between the roll and the transfer paper can be shortened to reduce oil consumption and extend the life of the roll.

3 and 5 schematically show the mechanical and electrical configuration of a copying apparatus to which the present invention can be applied.

This copying device includes a copying device main body A, a document conveyance device B,
It also has a node C (Fig. 5).

The document conveyance device B operates in a mode in which the document is automatically conveyed onto the contact glass 15 each time a document is manually set, and in a mode in which the document is automatically conveyed onto the contact glass 15 when one or more documents are set. There is a mode in which device B is used as a pressure plate. 40 is a document feed belt, 4
Reference numeral 1 designates a document register finger, and 42 designates a renoid for pulling up the register finger 41 so that the document can be ejected after exposure is completed.

Images are created by the copying machine main body A, and the images created by the copying machine A are organized by the printer C. In this example, the number of computers connected is one, but a plurality of computers can be connected mechanically and electrically. First, in the copying machine body A shown in FIG. 3, the drum 20 is a photoreceptor using a selenium photoconductor, and is rotatably supported on a shaft and rotates in the direction of the arrow in response to a copy command or the like.

Inside the drum is a heater 39 (
Figure 21) is installed.

A fixed contact glass 15 and an operation display panel 25 are provided on the upper surface of the main body A of the copying machine. A scanning exposure means 1 is provided in the reflective shade for illuminating and scanning the original placed at a predetermined position on the contact glass 15, and forming the image at a fixed position on the moving photoreceptor drum 20. Exposure lamp 21. mirror 16.17,
18.19, the lens 14 is installed so as to maintain an optically conjugate relationship between the contact glass 1 and the exposed portion of the photoreceptor drum 20. The exposure lamp 21 and the mirror 16 are mounted on the first carriage 6, and the mirrors 17 and 18 are mounted on the second carriage 6.
During exposure scanning, the first carriage 6 is moved at a scanning speed v8 and the second carriage 7 is moved along a guide bar 22 at a scanning speed of 1/2 to the original screen by the scanning motor 2. By moving in parallel, the photosensitive drum 20 optically scans the original image while keeping the optical path length from the irradiation surface of the original image to the lens 14 constant, and moves at a fixed position.
The image is formed on top. To change the magnification, move the second carriage 7 along the guide bar 22, and when zooming out, move the mirrors 17 and 18 to the positions indicated by chain lines in the figure, move the lens l4 to the position 14', and zoom in. Sometimes, the mirrors 17 and 18 and the lens 14 are moved to their opposite positions, and then the first carriage 6 and the second carriage 7 are simultaneously moved to perform scanning, as in the case of the same magnification described above.

FIG. 4 shows an example of a moving device for the carriage 6, 7 for scanning and the carriage 7 for zooming. As shown in Fig. 4, the dynamic pulley 3°8, the idler pulley 9,
Semi-fixed pulley t (L.

By passing a wire around the tensioning pulley 11 and creating a first wire loop 4 and a second wire loop 5, the variable power motor 13 is rotated to displace the second carriage 7 to the above-mentioned position when changing the power. , during scanning, the scanning motor 2 is rotated and the first . The second carriage 6.7 can be moved synchronously.

Around the photosensitive drum 20, there are a main charging charger 28, an erase lamp 29, an exposure slit section, a developing device 26, a pre-transfer static elimination lamp 54, a transfer charger 30, a separation charger 55, a separation claw, a pre-cleaning static elimination charger 56, A cleaning device 32 and a static elimination lamp 33 are arranged. 34 is a fixing device configured in the same manner as shown in FIG. 1; 35 is a reversing device that inverts the transfer paper sent from the fixing device, reverses the front side and reverses the front side, and sends it to the double-sided coheat tray 36;
Further, 37 and 37 are first and second paper feed trays.

Next, each basic operation will be explained.

Before the drum 20 rotates, a static elimination lamp 33 and a pre-transfer static elimination lamp are used to remove toner already attached to the drum and uneven potential on the drum and prevent it from reaching the main charger 28 and the developing device 26. 54, separate charger 31. The transfer charger 30, the erase lamp 29, and the cleaning device 32 are driven. In this example, the cleaning device 32 operates under the condition that the power is turned on, but it may be configured to operate at the above-mentioned timing.

Due to this mechanism, the drum surface potential after passing through the static elimination lamp blade becomes Ov even after a jam (paper jam) or the like.

Next, the main motor 27 is driven to rotate the photosensitive drum 20 (point a in FIG. 6).

The leading edge of the image is determined by the control unit to be the part after the position passing the cleaning device 32.

After the drum 20 has rotated to its normal position, the document placed on the contact glass 15 is scanned by the first carriage 6, which is identical to the first scanning mirror I6 and halogen rung (exposure lamp) 21 shown in FIG. The original is scanned. The reflected light image from the original passes through the first mirror 16, second mirror 17, third mirror 18, movable lens 14, and fixed fourth mirror 19, and forms an image on the photosensitive drum 20. Prior to this, after the photosensitive drum 20 is charged by the main charger 28, unnecessary portions such as side portions are irradiated with light by the erase slang 29 to create an image pattern suitable for the transfer paper or the projected image. Thereafter, a latent image is created on the drum using the reflected light image. At this time, it goes without saying that the speed of the drum 2o and the speed of the first carriage 6 must be the same in order to obtain an image of the same size.

The latent image on the drum is visualized as a toner image by a developing device 26. The driving of the developing device 26, that is, the driving of the developing motor M4, is performed only when the latent image comes to the developing device 26 (point 5 in FIG. 6) for the purpose of prolonging the life of the toner. At this time, a dark or light image can be obtained by applying a bias potential (for example, 2 whispers +) to the roller of the developing device.

This developing bias, which determines the image density, is the 6th developing bias in this example.
As shown in the figure, when the photoreceptor drum 2o is rotating due to carrier adhesion to the photoreceptor drum 2o, a normal bias M (340V) is applied, and a bias η determined by density adjustment is applied only to the image area ZM. I'll do it like that.

On the other hand, the transfer paper in the first paper feed tray 37 or the second paper feed tray 38 is detected by a paper detector 53 by a paper feed roller (feeding roller) 50.
is sent until it is activated (period 1 in Figure 7). Then, after a rest period ((
Period t3 in FIG. ). The pause time is determined by the feed roller 50. This is to eliminate defects in paper feed amount due to slippage on the separation rollers 51. Registration roller 43
The transfer paper that has been on standby in this way is sent out by driving the registration roller 43 at the timing when the leading edge of the toner image on the drum 2o and the leading edge of the transfer paper match.

The superimposed body of the toner image and transfer paper is transferred to a transfer charger 30.
and sent to the separate charger 55. Photosensitive drum 2
The toner image on the paper is transferred to the transfer paper by the transfer charger 3°. At this time, due to the extremely smooth surface of the drum, the adhesion between the drum 2 and the transfer paper is strong. The potential of the transfer paper is lowered in the separation charger 55 to reduce the adhesion force, and the paper is separated by a separation process, and is sent to the fixing device 34 by the conveyor bell l-31, where heat and pressure are applied to the toner to make it adhere to the toner, and the paper is discharged. do. Since a small amount of toner remains on the surface of the drum 20 after transfer, a pre-cleaning static elimination charger 56 (negative discharge) is applied, the drum surface is cleaned with a brush blade, and the surface potential is increased with the next static elimination lamp blade. Keep constant. The method for removing static electricity is a lamp; LED.

EL or AC power supply may also be used. Then proceed to the next cycle.

These controls are preferably performed mainly in accordance with pulses generated in synchronization with the rotation of the drum or reference pulses for driving the drum.

The basic operations have been described above. Next, each part will be explained.

As already explained in FIG. 1, the heat roll fixing device 34 includes a heater roll 34g that includes heaters H1 and H2 (FIG. 5), and a rubber puncture roll 3.
4b is pressed from below with a lever 34c and an eccentric pressure cam 34d, and the transfer paper is passed between both the fixing rolls 34a and 34b, and the heater roll 34a
The oil is applied through the felt 34e. The amount of heat supplied from the fixing roll to the transfer paper for fixing is determined by the roll temperature T and the nip time t. In order to switch the pressurizing cam 34d to the pressurizing position and the non-pressurizing position, in this embodiment, the fixing pressurizing lens 60 (fifth
Figure) is provided.

The transfer paper that has exited the fixing device 34 is reversed by a reversing device 35 in the case of double-sided copying. FIG. 8 shows the configuration of the reversing device 35, and FIG. 9 shows a timing chart. When the transfer paper passes through the fixing device 34 and reaches the reversing roller 65, the paper is advanced upward by a lever 68 that pops out during reversal. After the trailing edge of the paper passes through the fixing device 34 and after a certain period of time (t-t in FIG. 9), the trailing edge of the paper passes over the lever 68 of the reversing roller 65. At that time, when the return roller 66 is attached to the paper, the paper advances in the opposite direction, and moves toward the lower guide 67 in FIG.
It enters the double-sided copy tray 36 through the roller 69.

44 is a side guide plate of the double-sided copy tray 36, 45 is a drive motor for the drive screw 46 of the double-sided copy tray, 47 is a paper feed tray 37, an upward drive Ml of 38, M2.48 is a chopper, and 49 is a sensor. .

A block 24 drawn at the lower left of FIG. 3 is a control device, the outline of which is shown in FIG. 5.

In FIG. 5, 7o is a power supply unit, and 71 is a CPU control circuit. 72 is a paper feed lift motor 47 (Mlt
M2), a variable magnification motor 13 (M3), a developing motor M4, fan motors M5 to M7, and a pre-transfer static elimination lamp 54. 73 is exposure lamp 2I
It is a fuel/grease regulator. 74 is a control unit (fixing heater control unit) for the fixing heaters H1, H2 and the temperature sensor (thermistor) 61, and 75 is a control unit (drum heater control unit) for the drum heater 39 and the temperature sensor (thermistor) 62.

As shown in FIG. 21, this drum heater 39 is a cylindrical planar heater and is provided concentrically inside the photoreceptor drum and a little apart from the back surface of the photoreceptor drum, and the thermistor 61 is located outside the fixing roller 34a. ni′! Thermistor 62
is provided outside the photoreceptor drum 20, either in contact or without contact. The fixing heater control unit 74 includes a voltage converter 8 that converts the change in resistance value of the thermistor 61 with respect to temperature into voltage.
0, A/D that converts the voltage from the converter into a digital value
It has a converter 81 and a semiconductor switch 82 for controlling the power of fixing heaters H1 and H2. Fixing heater control unit 75 similarly includes a voltage converter 83, an A//D converter 84, and a semiconductor switch 85. Voltage converter 8
0 and 83 can be constructed by dividing the power supply voltage VCC with thermistors 61 and 62 and variable resistors VRI and VB2, respectively, as shown in FIG. 22, for example.

Again in FIG. 5, reference numeral 76 denotes each charger 28, 30, 55°5 for charging, transfer, separation, and neutralization before cooling.
6 and a high voltage power supply unit for developing bias.

This is a control unit (servo motor control unit) for the 77u scan-E-12 and main drive motor 27.

FIG. 1O shows an example of the operation display panel section 25. As shown in FIG.

First, when a power switch (not shown) is turned on, the following display lights up in the display areas 90 and too.

■ Power display @ Please wait O Set number of sheets List I ■ Number of copies Waiting time until copies are made ■ Density selection display: d and h light up O paper, size: 5x the set size
The key displays displayed on the paper size display section 102 consisting of 7 dots: ■ Paper feed selection display ■ Same size ■ Zoo% display Next display.

(r) Power saving key 101 Press this key to enter the power saving mode, and press it again to return to the original mode.

Operation (in power saving mode) ■ Power, power saving lamp lights up @ ■ Turns off all displays except O Power saving key is disabled ■ Drum and fusing heater are controlled to a predetermined temperature lower than normal ■ Return mode to normal ○ Paper feed tray If the power saving mode is entered while the paper is moving up and down, the movement of the paper feed tray will be prohibited after the movement is complete.When the power saving mode is canceled, the mode will be set to normal (1 size, 1st
Paper feed tray, density center, printer, duplex, reverse, cancel multiplex, set number of sheets %1#). The power save key is activated during copying (until it is ejected or until paper is fully loaded into the buffer tray 36).
is prohibited and valid under other conditions.

(2) Print key 103 The copy operation is started by pressing this key.

Can be entered only when copy operation is enabled.

(3) Interrupt key 104 If you press this key during copying, copying will stop at that cycle if it is before paper feeding, or after the copying is finished if paper is being fed or has finished (transfer paper will be stopped). After ejecting or entering the buffer tray), store the mode and display at that time, set the mode to normal, and set the number of sheets to 1k111.
Set the number of copies per copy to O〃 (unlit).

When entering interrupt mode, the interrupt display N-〆 lights up. Pressing the key is valid multiple times during standby and copying, and the mode at the time the copying is completed is adopted.

The same applies to pressing the interrupt copy button; if the interrupt display is off when copying is completed, the mode is returned to normal, and if the interrupt display is lit, the interrupt mode is maintained.

When the interrupt key 104 is pressed an even number of times, the operation returns to the original state, but the mechanism stops. In this case, copying continues by pressing the print key.

When a jam occurs or a machine abnormality occurs, the number correctly discharged or the number accommodated in the buffer tray 36 is stored.

(4) Numeric keypad 105 The numeric keypad 105 is a key for setting the desired number of copies, and a two-digit number can be entered using this key. During copying, pressing the first %QI key and the third digit key on the numeric keypad is disabled when the set number is not 1\1#.

Further, the entered key is displayed as the number of cents, and the contents of the key are stored in the memory.

The numeric keypad is also used for the following purposes.

Indicates the amount of blank space to add a binding margin to the copy image.

The blank amount can be set by pressing the numeric keypad 105 while pressing the right blank key 205 or the left blank key 206. The setting amount is from 0 to 16, and 1
If the number is set to 6 or more, key manual operation is prohibited.

If the number is 16 or more, 16 may be set when the key is pressed or released.

When the blank key is pressed, even if the number of set sheets is displayed at 10 o'clock, the ant of is turned on without turning it off.

(5) The clear/stop key 10 has two functions: a clear function and a stop function.

■ Clear/stop key 1 after pressing numeric key 105
When 06 is pressed, the number is changed, and this key changes the display to set number of sheets per month 1, number of copies per sheet - Ql
(%Q# does not light up) and also set the memory to the same value.

@ Pressing the clear/stop key 106 while pressing the blank key 205 or 206 changes the blank amount, and this key changes the display to the set number of sheets 1.
o” (%□j lights up), number of copies displayed %x” (
'x' remains unchanged) and the memory is set to the same value.

Continuous copying is stopped by pressing the clear/stop key 106 during O copying.

- If there is paper that is being fed and is being copied when the stop key is pressed, the machine will stop after that copy is completed.

Also, if paper is not being fed when the key is pressed, the cycle ends with that.

- By pressing this key, the display changes as follows. The number of sheets in a set and the number of copies per copy remain unchanged.

・Press the button after setting the number to set, set the number of copies to -4, ki□
Set to tr.

(6) Dark, tingle keys 107, 108■ Use these keys to change the density of the image.

When the power is turned on, auto-reset, interrupt special mode is selected, the concentration selection display is lit at the normal position 1ゝd〃.

@ When you press the key 107, the display is d − + C→
...and the image becomes distorted.

By pressing the row key 107 for a certain period of time of 0.3 (8) or more, the row automatically moves in one direction (if it goes to both ends, it stops there).

The same goes for the light key 108, in which case it moves toward N light.

Pressing the light and dark keys 107 and 108 at the same time returns to the normal position.

(7) Paper feed key 109 ■ Use this key to select the paper feed tray.

Pressing it an odd number of times changes the paper feed tray, and pressing it an even number of times returns it to the original position.

@ If pressed during copying, the paper fed at that time is ejected and stopped, the number of cents does not change, and the number of copies per copy becomes 10 (light off).

When pressed under conditions other than O@, only the paper feed tray changes, but the number of cents and the number of copies do not change.

Even when a jam occurs at O0, the display remains @.

■ If pressed during the first copy of double-sided or multiple copying, the following operations occur.

■ If the paper size is the same, change the paper feed tray, but the number of sheets set and the number of copies per copy will not change.

■ If the paper size changes when changing the paper feed tray, the number of sheets set and the number of copies per copy do not change, and the paper in the buffer tray is prepared to be ejected in blank mode. As mentioned above, the blank paper mode is a mode in which paper is fed and ejected without performing a copying operation.

■ After pressing the paper feed key 109 again to return to the original state, the blank paper mode is canceled.

The number of sheets set and the number of copies per copy do not change.

θ Paper feed key 10 during the second copy in duplex and multiplex mode
When 9 is pressed, the paper fed at that time is ejected and the machine stops.

The number of sheets set and the number of copies per copy do not change.

(8) Size uniformity key 110 Set by pressing it an odd number of times, and when set, the size uniformity display lights up.

In this mode, the following operations are performed: 0) The magnification ratio is automatically selected according to the original size and the paper size of the selected paper feed tray.

■ If the optimum magnification ratio is not available, a mode in which the image is placed on the transfer paper is selected preferentially, and the uniform size display is flagged to enable copying.

■ The automatic timing is when the original is set and the size is detected, and is prohibited when there is no original, no transfer paper, or while the original is being transported.

■ During automatic selection, the start of copying is stopped until the selection is completed.

(9) Same size key 111 Pressing this key returns the variable magnification mode to the same size and lights up the same size display in the display area 90.

This key is prohibited during copying.

00) Reduce key 112 Pressing this key selects the reduction mode.

1st reduction 1st reduction 2nd reduction 3rd reduction 3rd reduction 1st reduction 1st, 2nd, 3rd, 1st, etc. Repeat the reduction O Hold this key constant If you press the button for more than a few seconds, for example, the reduction ratio will change automatically.

In this example, up to the third reduction is shown, but in the case of multiple scaling, l=n reduction is repeated.

The reduction rate at that time is displayed in the display area, especially in the form of N%,
It is further shown in a reduced size.

01) Enlargement key 113 By pressing this key, the enlargement mode is selected and a related display and an enlarged display are displayed in the display area 90.

If the combination of the same size, reduction, and enlargement keys is pressed at the same time, the same size is selected.

02) Random variable magnification key 114 ■ This key is the key to set the stepless mode. If you press it an odd number of times, it will enter the random variable magnification mode and the random display will light up. 0 @ Pressing this key will change the previous variable magnification. The mode is memorized and set to random equal magnification mode, and when this mode is canceled, it becomes the mode before random magnification mode.

θ ■ In random mode, if you press the equal size key, the mode will change to the same size, the display will be displayed at the same size, and the chi display will change to 10.
It becomes 0%.

■ When you press the reduction key, each time you press the key, n
% line reduction, the same size display disappears, the reduced display lights up,
The display shows the reduction ratio at that time.

When the reduction key 112 is pressed for a certain period of time or more, the reduction rate is automatically decreased at a certain interval, stops at the minimum reduction position, and is instructed to the operator by a buzzer, a reduction display, and a blinking reduction rate display.

(It also has a function to inhibit the above function using an internal SW.) When the enlargement key 113 is pressed, the magnification ratio changes in the enlargement direction.

03) Ent key 201 Ent key 201 is used when using the computer C in the int mode, and when pressed an odd number of times, the int key 201 enters the int mode and lights up the display 201'. Pressing it a few times will return it to its original position.

(141 Stack key 202 The stack key 202 is used when using the printer in stack mode. The operation of the key is the same as the stack key.

Start key 2011 Stack key 202 is invalid when the node is not connected, and releases each mode when the node is disconnected.

(I5) Single-sided original key 203 Pressing this key switches to the double-sided mode using single-sided originals, and lights up the display 20I.

In this mode, to add a binding margin when facing the back side,
The paper is ejected approximately 5B earlier than the image (there are no particular regulations regarding 5B).

06) Double-sided original key 204 Pressing this key enters the double-sided mode using double-sided originals, and lights up the display.

a Double key 207 Pressing this key enters a mode for copying multiple images on the same surface. When this mode is entered, the display 207' is turned on.

Only one of the single-sided original mode, double-sided original mode, and double-sided original mode can be selected, and the mode corresponding to the last pressed key is set.

Power supply 08:00■ By turning on the power switch, the power supply unit 70 (
When the power supply is turned on (Fig. 5), the CCPU control circuit 71 is energized, the CPU is reset, and after the reset signal is sent, the mode of each element is specified, and then data is stored in the non-volatile memory (including battery-backed type). move to main memory.

In this example, this data includes the jam location, serviceman call location (machine abnormality location), number of jams (including the number of times for each location), number of copies per size, total number of copies, and each mode (variable magnification, enlargement, duplex etc.) Includes the number of separate copies and the number of jams.

■ Next, perform the initial settings.

Here, set the operation panel to the following mode. ■Display■ Number of copies set 1ゝ1// @ Number of copies per copy 11 off" (Io// )○
Density selection It d“lit (normal)○
Magnification ratio display 100% ■ Power supply element lit G When fusing and drum warm up, "Please wait" lights up ■ Other elements turn off ■ Mode ■ Book mode with same size ■ Sorter OFF θ Both sides OFF ■ Blank OFF ■ Reverse 2 Heavy 0FF G Size unification OFF ■ When the first and second paper feed trays both have paper reeds, use the first paper feed tray 37, and when there is no paper on the first paper and there is paper on the second paper feed tray, use the second paper feed tray. The paper feed tray 38 is selected, and if both the first and second sheets are not available, the first paper feed tray 37 is selected. 1000 on the first paper feed tray 37
Sheets can be set, and there are 500 sheets of paper on the second paper feed tray 38.
It is now possible to set a set. Also, if the paper feed selection key 109 is pressed at this time, the current mode will be selected.

■Mechanical movements■ Including the initial setting of the paper feed tray remaining amount detection circuit, the paper feed tray is first lowered, and then raised when it reaches the lowest position.

The flow at this time is shown in FIG.

5. In step 11.1, it is determined whether it is "initial setting", and if it is initial setting, proceed to step 11.2.

At Ste, p 11°2, it is determined whether the 11 first paper feed 37 has been lowered. This determination is based on the lower limit switch 88 (Fig. 12) that is activated when the paper feed tray is lowered (lowest position). If it is lowered, proceed to 5t6p 11.4 and motor M1
i Stop the battery from dropping and clear the remaining amount counter.

This remaining amount counter is based on signal pulses obtained from a pair of light emitting/receiving elements 49a and 49b located on both sides of the chopper or code disk 48 as shown in FIG. 14 (see FIG. 15).
The counter is reset to zero if the lower limit switch 88 is activated. If it is not lowered, proceed to S t6p11°3 and rotate the motor M1 in the direction to lower the paper feed tray.

5 step 11. At step 11.7, the above-mentioned determination and control of the motor M2 are performed for the second sheet feeding tray 38.

Ste, p In 11.8-11.13, Ste, p
Control is performed to raise the paper feed tray that was lowered in steps 11.2 to 11.7 again using the paper feed tray lift motors M1 and M2 (i = i).

ste, p 11.8, if the upper limit switch 86, which operates when the paper feed table rises to the correct position, is OFF, 5t
al) Raise the paper feed tray at 11.9, and if it is raised at the correct position 1, stop raising the paper feed tray at 5t6ipH,10.

5trep11.11 to 11.13 are shown for the second paper feed tray, and the functions are 5te1.1 for the first paper feed tray. Same as p 11.13 to 11.10.

st. At p 11.14, it is determined that both the first and second paper feed trays have risen, and at 5top 11.15, the initial setting router determination flap is reset to inside.

Automatic selection is determined at 5top 11°16, and if the mode is to automatically select the paper feed tray, the process advances to 5t8p11.17 (the automatic selection flag is reset by pressing the paper feed selection key).

Also, if the paper feed selection key is pressed during the process, this flag becomes ``0'' and the paper feed is not automatically selected.

The following operation is performed at 5t8p11°17-11.20.

■ If there is paper on the first paper feed tray, select the first paper feed tray ■ When the first paper feed tray is at Pend (paper end), the second paper feed tray
If there is paper on the paper feed tray, select the second paper feed tray. The presence or absence of paper is detected by a paper end detector 87 (FIG. 12). That is, as shown in FIG. In the case of , it is in the state shown in Fig. 13 (as shown in BL), A, and in the upright position, and in the case of paper legs, it is in the state that is held down by the paper 87 as shown in Fig. 13 (cl).

■ If there is no paper in both the 1st and 2nd paper feed trays, the 1 Select the paper feed tray.

■ Figure 16 shows the flow of detecting the remaining amount of paper in the paper feed section.

This function is available when the paper feed tray is not set.
(out of paper), the display is turned off when the paper feed tray is lowered,
This is a flow that is displayed when the paper feed table is raised or at a fixed position. - The code conversion in 5t8p16.8 is to convert the counter into a code that is easy to display, since it is binary. This can also be done using a decoder etc. For example, as shown in FIG. 18 (al), the voltage ■1
The data may be extracted as a digital signal, converted into digital data by the A/D converter 63, and displayed on the display 89 through the decoder driver 64. The relationship between vl, which is the A/D input, and the remaining amount display in this case is shown in Figure 18 (bl). In this case, the relationship between the displays will deviate greatly due to adjustments, etc., so it is difficult for the car to make the change more than 5 pulses/remaining amount display. Up to 200 pieces, 2 pieces are displayed, 40 pieces
This is an example in which 1 or more images are displayed as 4 images.

FIG. 19 shows operation steps C1-f when paper remains on the bumper tray (double-sided copy tray 36) when the power is turned on. Further, FIG. 20 shows the timing chart.

The flow diagram shown in FIG. 19 will be explained.

At 5tap19.1, it is determined whether the buffer tray control routine when the power is turned on is in progress. As shown in FIG. 20, normally an initial flag is set when the power is turned on, so the process proceeds to the next step.

5 step 19.2 to determine whether the fixing is heated. In this case, the determination may be made at a low temperature (including a temperature lower than the actual operating temperature) at which there is no problem even when driving the fixing device. Warm U
If you press P, proceed to the next step.

If it is not warmed up Skip this flow and move on to the next flow. Go and come back here again.

st,>,919.3 Determine whether there is paper in the buffer tray. If there is paper, proceed to the next step; if not, proceed to 5step 19.13.

Main motor 2 at 5tep 19.4~19.7
7. Activate a series of units related to driving the main motor, such as the fixing pressure solenoid 60.

The fixing pressure solenoid 6o is The toner image is fixed using pressure and heat. In this case (power supply (N time), the paper is only ejected, so There is no need to apply pressure.

5tep Feed paper until the buffer tray runs out of paper at steps 19.8 to 19.10. Since it is not good if a jam occurs at this time, the jam is checked using Steplg and g.

5tep 19. Obtain the time until the last paper is ejected from the buffer tray at 11.

Since all the paper was ejected at 5tep 19.12,
Stop the main motor.

At 5tep 19.13, the flap (initial element) that activates these sequences is reset.

If the print button is pressed after 5tep 19.11, the print routine is entered by skipping 5tep 19.12u, but the initial 1 flap is reset.

■ Heater control FIG. 26 shows a flow diagram of heater control.

At 5tep 26.1, the output of the sensor 61 of the fixing section is set to A.
/D conversion. FIG. 23 shows the rise-up characteristics of the fixing system or photosensitive drum system at a temperature of 1 fT, and FIG. 24 shows the relationship between the voltage V input to the A/D converter and the temperature T in the circuit configuration of FIG. 22. , and FIG. 25 shows that A for the input voltage V.
'/Relationship between the outputs obtained from the D converters 81 and 84? It shows.

The temperature T after A/D conversion at 5tep 26.2 is 200
Check whether the temperature is above ℃. If it is 200°C or higher, it is considered an abnormal temperature and the process goes to 5step 26.3, the fixing abnormality lamp is turned on, and the heater I is turned on.

11 (Hl, H2) is turned off.

If the temperature is 185℃ or higher at 5tep 26.4 (
185°C (T (22°C)) Go to Step 26.5 and set warm-up 1, indicating that the fixing system color ohm has been UP.Furthermore, turn off heater 11 (2) and reset the flag indicating that the fixing temperature is low. .

Check to see if the temperature is below 150°C at 5tep 26°6. If it is below 150°C, go to 5tep 26°7 and set the heater I, UfONL, and 1" where the humidity level is low.
Set the flag.

This flag is set during copying. copying is interrupted and the fusing temperature is restored. Wait for the copy to start and then start copying again. do. or copy by this flag - You can slow down the speed.

Check if the temperature is 184°C or less at 5tep 26.8.

If the temperature is 184° C. or lower, go to 5step 26.9 and turn on heaters I and It.

The temperature control of the fixing section is completed in steps 26.1 to 26.9 above, and then the process proceeds to drum temperature control.

5tep 26. A/D convert the output of the drum temperature sensor at 10K.

At 5tep 26.11, it is checked whether the drum temperature is 60°C or higher. If it is 60°C or higher, the process proceeds to 5tep 26.12, where the drum temperature abnormality lamp is lit and the heater is turned on.

At 5tep 26.13, it is checked whether the drum temperature is 40°C or higher. If it is 40°C or higher, the process proceeds to 5tep 26.14, where warm-up 2 is set to indicate that the drum system has warmed up.

At step 5 26.15, check whether the drum temperature is below 30°C. If the temperature is below 30°C, proceed to step 5, step 26, and set the flag ``drum temperature low 2'' and turn on the drum heater. If this flag is set during copying, copying will be temporarily suspended.

At step 5 26.17, check whether the drum temperature is below 39°C. If the temperature is below 30°C, 5 step 26. ．． Proceed to step 18 and turn on the drum heater.

The above operations control the temperature of the fixing system and drum system. In temperature control, a difference is created between the ON temperature and OFF temperature of the heater to widen the fluctuation of the heater, but it is also possible to eliminate this difference.

Since the temperature is converted into digital data by A/D conversion,
It is necessary to set the resolution of /D as follows.

Tolerance of fixing temperature/Bit, (Temperature II'/Bit)For example, to make it 185 degrees 1℃, it is necessary to keep it below 1℃/Bit, but considering the tolerance of parts, it is 0.25℃, which is less than 1/4
/Bit or less will result in better control. By making the control routine i above pass within 3 ms of the half-wave time 8 of 60H2, control can be performed every half cycle, and fine-grained control can be achieved.

When changing the temperature using an external switch, etc., the conditions of the external switch, etc. can be included in the temperature comparison data, or the temperature can be changed using the VR (FIG. 22) before A/D conversion.

■ Waiting time display Figure 27 shows a flowchart for displaying warm-up time. This time the fuser drum will display any longer force.

The fixing temperature and warm-up time have a relationship as shown in FIG. 23, and from this, the time until the fixing warms up is determined and displayed.

Check whether the fixing temperature is below T1 in step 27.1,
If it is below T1, go to 5tep 27.2, Ti1
Insert tl (waiting time is 9 minutes) into t1.

Check if the fixing temperature is below T2 in step 27.3.
If it is below T2, go to 5tep 27.4, Tiμ
Insert t2 (waiting time 8 minutes) into m.

At 5tep 27.5, check whether the fixing temperature is below T3. If it is below T3, go to 5tep 27.6 and check if the fixing temperature is below T3.
Insert t3 (7 minutes of waiting time) into tμm.

Check whether it is below Tn at step 27.7, and
If it is below, go to 5tep 27.8 and insert tn (wait time 2 minutes) into Tiμm.

At 5tep 27.9, add 1 minute to Tiμm.

At step 5 27.10-27.18, the drum temperature is checked in the same way, and the waiting time is entered in Tiμm.

At 5tep 27.19, check Tiμm=Tiμ2f and if they are equal, go to 5tep 27.20.

At 5tep27.20, it is checked whether T i p 1=O or not, and if it is 0, the waiting time is not displayed because it is warmed up.

Ti μm and Ti at 5tep 27.21;2
Check which one is thicker and display the larger force.

G Copying Operation■ First, when the print button 103 is pressed, the motor 27 rotates, which in turn drives the photosensitive drum 20, fixing device 34, reversing device 35, etc. In order to make the surface of the photoreceptor drum 20 uniform, a cleaning device 32 and a static elimination lamp 33 are used.
, erase lamp 29, transfer charger (Corotro/)
Activate 30ffi.

■ Paper feeding operates as follows (see Figure 7).

First, the feed roller 50 is driven to feed the paper until the leading edge of the paper reaches the paper feed detector 53, and when the paper feed detector 53 is activated, the feed roller 50k is turned off. Send it like this
To eliminate defects in paper feeding amount due to slippage in a delivery roller 50 and a separation roller 51. Next, at time t2 in FIG. 5, the feeding roller 50 is driven again.

72 in FIG. 5 takes the time to reach t2)0 even if the slip of the feed roller 50 and the separation roller 51 is included. t3
The width is set to 1] from the time taken for the leading edge of the paper to reach the feed roller 52 until the leading edge of the next paper reaches the paper feed detection 53.

As the transfer paper moves, the scanning motor rotates to expose the original. The light forms a latent image on the photosensitive drum 20, the developing device 26 develops it, the transfer charger 30 transfers the toner to the transfer paper, the separation claw releases the transfer paper from the drum 20, Fixing device 34
It is fixed and discharged.

The developing device 26 is driven only when the latent image comes to the developing device 26 in order to prolong the life of the toner.

The developing bias that determines the image density is applied to prevent carrier adhesion to the photoreceptor drum 20, etc., by applying a normal bias (340V) when the photoreceptor drum 20 is rotating, and applying a bias determined by density adjustment only to the image area. Make it look like it's running. (See Figure 6).

(2) The reversing device 35 is a device for reversing the copied transfer paper, and for double-sided copying, the reversing device 35 reverses the copy and stores it in the double-sided copy tray 36. At this time, since the image side is on the upper side, the next copy will produce an image on the lower side, making double-sided copying possible. The transfer paper is transferred to the fixing device 3.
4 and reaches the reversing roller 55, the lever 68 that pops out at the time of reversal causes the paper to move upward. After a certain period of time (11 in FIG. 9) after the trailing edge of the paper passes through the fixing device, the trailing edge of the paper passes over the lever 68t of the reversing roller.

At this time, when the return roller 66 is attached to the paper, the paper advances in the opposite direction, follows the lower guide in FIG. 8, and enters the duplex copy tray 36. The return roller 66t may be released at any time after the trailing sound of the paper enters the roller B in FIG.

Flip the paper in this way.

■ Both sides 1. I
If there is any paper remaining, it will be duplicated with the next copy paper, so it is ejected and the normal copying operation is then performed. 28th
A flow diagram and a timing diagram at that time are shown in FIG.

When the print button is pressed, the process goes to step 28 in FIG. 28, where it is determined whether or not an interruption is occurring, and if so, the process proceeds to the copy routine.

This is because interruptions can be made during double-sided copying.

At step 28.2, it is determined whether the mode is to put paper into the buffer tray 36. When the mode is not to put paper into the buffer tray, go to the copy routine.

Check whether the print button is pressed in the middle of copying in step 28.3. If copying is in progress, go to the copy routine.

5step 28. Check whether there is paper in the buffer tray at step 28.4. If there is no paper, go to the copy routine.

At steps 28.5 to 28.8, the paper from the buffer tray is discharged while checking for jam. At this time, no charge is applied and no image is created. Set to blank page mode.

Load paper into the buffer tray from above mode, there is paper in the buffer tray.

First, empty the buffer tray and then enter the normal copy routine. By doing this, the correct number of copies can be made without the paper being mixed up with the previous transfer paper in the buffer tray. During normal copying, if there is paper in the buffer tray, it can be ejected. At this time 5tep28
．． It goes without saying that the judgment in step 2 can be made, for example, by turning the image backwards and reversing the YXN of the judgment.

When printing without creating an image in blank page mode, the charge management counter will count up and change to Guy-sama (talk counter key counter, etc.).

① Control of reversal mode The reversal function explained in ③ executes the mode shown in Table 1 by operator operation, optional equipment, etc.

* Even if the inversion key is pressed, the same inversion occurs... When the inversion device 35 is driven, "ゝ○" is ejected...
・When discharging the transfer paper 110 "Discharge... When transferring the transfer paper to the buffer tray 11 Q // Sort... The type that is reversed in the sorter 15 Types Printer 2... Type that is not reversed within the sorter In the blank paper mode (period a-b in Fig. 29) in which the paper is ejected from the buffer tray 36 without an image on it as shown in Fig. 3, the charger 28 is turned off to prevent unnecessary toner from getting on the transfer paper. , turn on the erase lamp 29, set the developing bias to normal, and turn off the developing device 26 as the case may be.Furthermore, in accordance with the present invention, in order to prevent a drop in the fixing temperature and prevent dirt, the pressure on the roller of the fixing device 340 is released. In order to stack the paper in order after being ejected during double-sided printing, it is turned off in the blank paper mode even in the reverse mode.

■About the blank paper mode The blank paper mode is used for double-sided copying at one time, and is used as an eject mode without making an image on the back side.This mode occurs at the following times (3rd
(See Figures 0 to 33).

■ Both sides! , 11. When the mode is canceled during multi-mode copying.

@ Both sides 1. II. In the middle of multiple mode copying, how many sheets to set? when changed.

0 When the paper size is changed during front side copying in duplex I, ■, or multiplex mode. In this case, if you return the paper size to its original size, the blank paper mode will be canceled. Do not change to blank page mode when changing to back side copy at one time.

@Double-sided l=n, when flipping over the buffer tray during copying in multiplex mode.

■ During back side copying, when the condition is that the number of sheets set ≦ the number of sheets per copy, and there is still paper left in the buffer tray.

0 When the paper source is changed or the paper size is changed. In this case, returning the paper to the paper feed tray will cancel the blank paper mode.

■ Both sides 1. II. When changing the number of sheets set during multiple mode (in the middle).

When in the above-mentioned blank paper mode, the paper is ejected according to the procedure (2) above for ejecting paper from the buffer tray.

In this example, we have shown an example where the print button is turned on to eject the paper, but
It goes without saying that the paper may be ejected as soon as the blank page mode occurs. FIGS. 30 to 33 show flowcharts when the blank page mode is generated.

As described above, the present invention can be used for double-sided copying and single-sided copying, and moreover, during back-side copying, at least a part of the operating means is inactivated or at least a part of the image forming process is not performed. In a copying machine capable of a blank paper mode for conveying copies and producing a copy with a blank back side, when the blank paper mode is selected and executed, the pressurizing force of the pair of rolls of the heated roll fixing device is reduced or canceled. Because of this, there is no loss of fixing heat taken away by the transfer paper during blank paper mode, and the durability of the fixing roll is increased.

In addition, the oil-applied type heat roll fixing device does not consume any more oil than is necessary since it has a blank paper mode.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the configuration of a heat roll fixing device that can reduce or cancel the pressurizing force according to the present invention, and Fig. 2 shows the relationship between the pressurizing force, the amount of heat supplied to the paper, and the nip width, as well as the nip time and the supply to the paper. A diagram showing the relationship between the amount of heat and the nip width, FIG. 3 is a schematic diagram of the configuration of a copying apparatus to which the present invention can be applied, FIG. 4 is a perspective view of the configuration of its scanning exposure means, and FIG. A block diagram, FIG. 6 is a timing diagram showing the operation of the developing device, FIG. 7 is a diagram showing the configuration and operation timing of the paper feed section,
FIG. 8 is a schematic diagram of the reversing device section, FIG. 9 is a timing diagram showing the relationship between the operations of the fixing section and the reversing device section, FIG. 10 is a plan view of the operation display device panel, and FIG. 11 is a paper feed tray. 12 is a diagram showing the relationship between the vertical movement of the paper feed tray, the upper and lower limit switches, and the paper end detector, and Figure 13 is a flowchart for setting the vertical position of the Fig. 14 is an explanatory diagram of the pulse generation mechanism for detecting the remaining amount, and Fig. 15 shows the pulse from this pulse generation mechanism?The paper feed tray operates the lower limit switch. 16 is a flowchart for operating and displaying the remaining amount counter, and FIG. 17 is a diagram illustrating the relationship between the display and the remaining amount of paper. Figure 18 (al is another specific example in which the display is performed by an A/D converter, No. 18)
Figure (bl is a diagram showing the relationship between the A/D input and the remaining amount, the first
Figure 9 is a flowchart showing the operation when there is paper left in the buffer tray when the power is turned on, Figure 20 is a timing diagram at that time, and Figure 21 shows the temperature of the fuser heater control unit and photoconductor drum heater control unit. A schematic diagram of the configuration of the control unit, FIG. 22 shows a specific example of the temperature detection circuit (2),
Fig. 23 is a diagram showing the warm-up characteristics of fixing or drum temperature, Fig. 24 is a diagram showing the relationship between the voltage A/D converted in Fig. 22 and the temperature at that time, and Fig. 25 is the diagram of Fig. 22. A diagram showing input/output characteristics of the A/D converter, FIG. 26 is a flowchart showing control operations for fixing and drum temperature, FIG. 27 is a flowchart showing warm-up time regarding fixing and drum temperature, and FIG. 28 Figure 29 is a flowchart showing the operation of ejecting paper and entering normal copying operation when paper remains in the buffer tray when the print button is pressed, Figure 29 is its timing diagram, Figures 30, 31, and 32. 33 and 33 are flowcharts respectively showing when the blank page mode is generated. DESCRIPTION OF SYMBOLS 1...Scanning exposure means 13...Motor for variable magnification 4...Lens 15...Contact glass 20-...Photosensitive drum 21...Light emitting lamp 24...Control device 25...Operation Display device panel 26...Developing device 27
... Main motor 28 ... Main charger 29 ... Erase lamp 30 ... Transfer charger 32 ... Cleaning device 33 ... Static elimination lamp 34 ... Fixing device 35 ... Reversing device 36
...Double-sided copy tray 37...First paper feed tray 38.
...Second paper feed stand 54...Pre-transfer static elimination lamp 5
5 Separation charger 56 Pre-cleaning static elimination charger 60 Fixing pressure solenoid 61.62 Temperature sensor 65 Reversing roller 66 Return roller 71 CPU control circuit Figure 1 Figure 2 Figure 6 Figure 7 Figure 8 Figure 12 Figure 13 Figure 14 Figure 15 Figure Lower V switch 1ν+B8 Figure 17 Remaining amount Figure 20 Figure 21 Figure 28 Figure 29 Figure 30 Figure 32 Figure 33 Continued from page 1 0 Inventor Toshio Watanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. 0 Inventor Tsutomu Yamagami 1-3 Nakamagome, Ota-ku, Tokyo No.6 Inside Ricoh Co., Ltd.

Claims (1)

[Claims] It is possible to selectively use double-sided copying and single-sided copying, and when copying the back side, at least a part of the actuating means is deactivated or the copying material is conveyed without going through at least a part of the image forming process. A double-sided copying machine equipped with a fixing pressure adjusting device, which has a blank paper mode capable of obtaining a blank copy, and when the mode is selected and executed, the pressing force of a pair of rolls of a heat roll fixing device is reduced or canceled. Device.